A diameter of a semiconductor substrate has been larger with rapid progress towards miniaturization and high integration in a semiconductor device. The semiconductor substrate is thinned by using such as polishing and separated to semiconductor chips by using such as dicing in processing a back surface of the semiconductor substrate. However, when a thickness of the semiconductor substrate is thinned down to below 100 μm, a crack and a lack are easily generated in the semiconductor substrate during processing or carrying the semiconductor substrate. Japanese Patent Publication No. PH10-82778 discloses an approach for preventing the crack and the lack generation in the semiconductor substrate. Furthermore, processing and carrying on a thinned semiconductor substrate between processing steps of evaporating a metal electrode film and processing steps of dicing the thinned semiconductor substrate are performed under a condition of sticking a protective tape on the surface of the thinned semiconductor substrate. Accordingly, the crack and the lack generation in the thinned semiconductor substrate can be suppressed.
Furthermore, mounting a thinned semiconductor device on a thin package, such as IC CARD and IC TAG, or a multi chip package (MCP) for layered semiconductor chips have been required in recent years. Therefore, a thinning technique obtaining a thickness of below approximately 90 μm on the semiconductor substrate having a diameter of over 200 mm is desired after fabricating semiconductor elements.
However, in the previous Japanese Patent Publication No. PH10-82778, processing and carrying the semiconductor substrate between processing steps of thinning the semiconductor substrate and processing steps of forming an electrode on the back surface of the semiconductor substrate are performed under a condition without sticking the protective tape on the surface of the semiconductor substrate. Accordingly, the crack and the lack by local stress in the semiconductor substrate are easily generated in the large diameter semiconductor substrate having a thickness of below approximately 90 μm between thinning the semiconductor substrate and forming the electrode.
Moreover, when separating thinned semiconductor substrate with a metal electrode film on the back surface to semiconductor chips by such as blade-dicing, a tipping and a lack on the cutting surface and the back surface near the dicing line of the semiconductor chip and a burr of the metal electrode film are easily generated, as hardness of the semiconductor substrate has a difference from that of the metal electrode.